abc Report Wide bore CT scanner comparison report version 12 February 2005 best choice best practice nww.medical-devices.nhs.

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1 abc February 2005 Report Wide bore CT scanner comparison report version 12 best choice best practice nww.medical-devices.nhs.uk

2 About MHRA evaluation reports. What you can expect. The Device Evaluation Service (DES) aims to provide independent and objective evaluations of medical devices available on the UK market. Specialist centres, mainly in NHS Trusts, do the evaluations under long term contract to, and in accordance with protocols approved by, the Medicines and Healthcare products Regulatory Agency (MHRA). The evaluations are usually of a unit supplied by the manufacturer. We would expect this unit to be representative of the product on the market but cannot guarantee this. Prospective purchasers should satisfy themselves with respect to any modifications that might be made to the product type after MHRA s evaluation. The reports are intended to supplement, not replace, information already available to prospective purchasers. The MHRA DES does not have access to any information held by the Agency in its capacity as the Competent Authority for the UK, apart from any information already in the public domain. The reports will contain data given by the manufacturer on the regulatory status of their devices but, apart from this, they are not an indicator of the regulatory status of a product. Occasionally, DES refers products to the regulatory arm of the MHRA for considerations of breaches of the legislation governing medical devices. DES plays no further part in any regulatory investigation that ensues and does not have advance notification of any regulatory action that may follow. How to obtain MHRA reports. To order evaluation reports, a copy of the publications catalogue or to sign up for our alert service contact: MHRA Orders Department, Room 1207, Hannibal House, Elephant & Castle, London, SE1 6TQ. T: +44 (0) F: +44 (0) E: des@ mhra.gsi.gov.uk Visit www. mhra.gov.uk for a comprehensive list of publications, details of forthcoming evaluations, services and contacts. Colour reports. Full colour versions of all reports published after 2002 are available from the Internet at

3 Wide bore CT scanner comparison report version 12 David Platten, Nicholas Keat Maria Lewis, Sue Edyvean ImPACT Bence Jones Offices St George s Hospital London SW17 0QT Tel: +44 (0) Fax: +44 (0) impact@impactscan.org Crown Copyright 2005 For more information on ImPACT visit Apart from any fair dealing for the purposes of research or private study, or criticism, or review, as permitted under the Copyright, Designs & Patents Act, 1998, this publication may only be reproduced, stored, or transmitted in any form or by any means with the prior permission, in writing, of the Controller of Her Majesty s Stationery Office (HMSO). Information on reproduction outside these terms can be found on the HMSO website ( or hmsolicensing@cabinet-office.x.gsi.gov.uk. The MHRA is an executive agency of the Department of Health. ISBN

4 Contents Introduction 5 Purpose of this report...5 Comparison method...5 Specification comparison...5 Scanners covered in this report...6 Table 1: Scanners covered in this report...6 Specification comparison 7 Table 2: Scanner gantry...7 Table 3: Couch...7 Table 4: X-ray generator...8 Table 5: X-ray tube...8 Table 6: Detection system...9 Table 7: System start-up and calibration...9 Table 8: Scan parameters...10 Table 9: Helical scanning...11 Table 10: Scan projection radiography (SPR)...11 Table 11: Manufacturers' performance data...12 Table 12: Factors affecting image quality...13 Table 13: Operator's console...14 Table 14: Main computer...14 Table 15: Image storage...15 Table 16: Image reconstruction on main console...16 Table 17: 3D reconstruction display...17 Table 18: Optional facilities...18 Table 19: Installation requirements...19 Table 20: Independent workstation...20 Table 21: Image transfer and connectivity...21 Appendix 1: ImPACT and the MHRA 22 Background...22 ImPACT...22 MHRA support to purchasers and users

5 Introduction Purpose of this report In May 2003 the UK Government announced a 90 million fund to replace all CT and MRI scanners installed before 1997 as part of the NHS Cancer Plan. ImPACT have produced comparison reports for each phase of the purchase program. The primary aim of these reports is to aid the equipment selection process by providing comparisons of CT scanners that are currently on the market. This report is for phase 7 of the Cancer Plan funding. There are four separate reports for six to ten, sixteen, and 32 to 64 slice CT scanners, as well as a report on wide bore systems. The scope of this report is limited to CT scanners that have a gantry bore wider than a standard system. These systems have been developed primarily for applications in radiotherapy planning. Comparison method The data given in this report are representative of the scanners as of February 2005, and are liable to change as the performance of individual scanner models is changed and upgraded. In particular, optional features such as workstations and software packages may be listed as standard for the scanner replacement programme, but may not be included in other, separate scanner purchases. There are two main areas for comparison of the scanners: performance and specification. None of the scanners in this report have been tested by ImPACT at the time of publication, so the scope of this document is restricted to a comparison of system specifications. Specification comparison The specification comparison is presented as a side-by-side summary comparison of the specification of each scanner, workstation and related equipment. It is grouped into a series of sub-sections relating to different aspects of the scanner, such as gantry, tube and detectors etc. Manufacturers supplied the specification data in response to a template issued by ImPACT. The data has not been verified by ImPACT. 5

6 Introduction Scanners covered in this report At the time of writing, there are four manufacturers of medical CT scanners that sell their systems in the UK (in alphabetical order); GE Medical Systems, Philips Medical Systems, Siemens AG and Toshiba Medical Systems. The wide bore models are listed below. Table 1: Scanners covered in this report Manufacturer GE Philips Siemens Scanner model LightSpeed RT AcQsim RT Somatom Sensation The is a four slice system with a gantry aperture of 80 cm. It has a maximum scan field of view of 50 cm, but is able to reconstruct images up to 65 cm using extrapolation methods. The fourth generation AcQsim RT from Philips is a single slice scanner with a patient bore of 85 cm, and a maximum scan field of view of 60 cm. The 20-slice Siemens Somatom Sensation has a gantry bore of 82 cm, with a maximum scan field of view of 50 cm. It is possible to reconstruct images up to 82 cm using extrapolation methods. The detector bank consists of 32 x 0.6 mm and 8 x 1.2 mm rows. The features the Siemens Straton x-ray tube, a new novel design of x-ray tube with fast cooling rates. Toshiba and Philips have recently announced new wide bore systems, but detailed specifications were not available at the time of publication. The Philips Brilliance CT Big Bore will be a 16-slice system with an aperture of 85 cm, a scan field of view of 60 cm, and a maximum image size of 60 cm. The Toshiba Aquilion Large Bore will also be a 16-slice system, with a gantry aperture of 90 cm, a scan field of view of 70 cm, and a maximum image size of 85 cm. 6

7 Specification comparison Table 2: Scanner gantry Generation 3rd 4th 3rd Slipring Low voltage Low voltage Low voltage Aperture (cm) Scan fields of view (cm) 25 and , 82 extended Nominal slice widths for axial scans (mm) 0.625, 1.25, 2.5, 3.75, 5, 7.5, 10 2, 3, 4, 5, 8 1.5, 2.0, 2.4, 3.0, 4.0, 4.8, 5, 6, 7, 8, 10, 12, 24 Tilt range (degrees) ± 30 ± 30 ± 30 Type of positioning lights Laser Laser Laser Accuracy of positioning lights (mm) Table 3: Couch ± 1 at any laser to patient distance ± 0.5 mm at centre of gantry ± 1 Couch top material Carbon fibre Carbon fibre Carbon fibre Couch top length and width (cm) 239 x 62 (42 just for cradle) 168 x 34 (just for cradle) 243 x 40 (just for cradle) Horizontal movement range (cm) Horizontal movement speeds (mm/sec) Accuracy/reproducibility of table positioning (mm) Scannable horizontal range without table top extension (cm) Scannable horizontal range with table top extension(s) (cm) Vertical movement range out of gantry (cm) Vertical movement range in gantry (cm) Minimum couch top height outside gantry (cm) Maximum weight allowed on couch (kg) Maximum weight on couch which still achieves stated performance specifications (kg) up to , 40, 50, ± 0.25 ± 0.25 ± (Axial), 160 (Helical & Scout) 170 (Axial), 160 (Helical & Scout) (±0.25mm) 205 (±1mm)

8 Specification comparison Table 4: X-ray generator Type High frequency High frequency High frequency Location Rotation assembly Rotation assembly Rotation assembly Power rating (kw) kv settings available 80, 100, 120, , 100, 120, 130, , 100, 120, 140 ma Range and Step size (5mA steps) (10mA steps) (1mA steps) Max. ma allowed for each kv 80kV: 400 ma 100kV: 420 ma 120kV: 440 ma 140kV: 380 ma 80kV: 400 ma 100kV: 400 ma 120kV: 400 ma 130kV: 320 ma 140kV: 320 ma 80 kv: 400mA 100kV: 400mA 120kV: 400mA 140kV: 360mA Table 5: X-ray tube Type and make GE Performix Pro Philips Rhino Siemens Straton Focal spot size(s) (mm), quoted to IEC 336/93 standard Settings at which focal spot changes from small to large Total filtration (inherent + beam shaping filter) at central axis (mm Al equivalent) 0.6 x x 0.9 Info. not available 6.8 (70kV, head) 9.5 (70kV, body) 0.4 x x 0.9 Automatically selected dependent on scan protocols 0.8 x 1.1 Not applicable Anode heat capacity (MHU) , equiv to 30 Maximum anode cooling rate (khu/min) Method of cooling Glycol to air Oil to air Oil to air Guaranteed tube life 1 year unlimited guarantee 100,000 revolutions 1 year unlimited guarantee 8

9 Specification comparison Table 6: Detection system Detector type Solid state (HiLight / Lumex) Solid State (Cadmium Tungstate) Solid state (Ultra Fast Ceramic) Number of detectors per row 888 (plus 18 reference elements) (1344 channels) Number of elements along z-axis Effective length of each element at isocentre (mm) Total effective length of detector array at isocentre (mm) Future option for more slices / rotation 16 x x 0.6, 8 x None currently None currently Yes Table 7: System start-up and calibration Power-on to warm-up time from fully off (mins) Tube warm-up time from 'cold' to operating temperature (mins) Time to perform detector calibrations at warm-up (mins) Recommended frequency for any additional calibration by the radiographer Time to perform these additional calibrations (mins) Total time from fully off to scanning in an emergency (mins) Included in tube warmup Part of warm-up procedure Once every 24 hours Not required Not required 13 (inc warm-up) Not required Not required < 3 Info. not available 4 5 9

10 Specification comparison Table 8: Scan parameters Reconstruction fields of view (cm) 9.6 to Extended scan field of view (cm) 65 Entire FOV uses standard reconstruction 82 Nominal slice widths (mm) and number of simultaneous slices (axial scans) Scan times for axial scans (s) * = Partial scans 2 x 0.625, 1 x 1.25, 4 x 1.25, 1 x 2.5, 4 x 3.75, 4 x 5 2, 3, 4, 5, 8 1, 2, 3, 4 0.6*, 1, 1.5, 2, 3, 4, 5 20 x 1.2, 10 x 2.4, 5 x 4.8, 4 x 6, 1 x 5, 2 x 12, 1 x *(option), 0.5 (option), 0.67*, 1.0s kv settings available 80, 100, 120, , 100, 120, 130, , 100, 120, 140 ma Range and Step size (5mA steps) (10mA steps) (1mA steps) Max. ma allowed for each kv 80kV: 400 ma 100kV: 420 ma 120kV: 440 ma 140kV: 380 ma 80kV: 400 ma 100kV: 400 ma 120kV: 400 ma 130kV: 320 ma 140kV: 320 ma 80 kv: 400mA 100kV: 400mA 120kV: 400mA 140kV: 360mA 10

11 Specification comparison Table 9: Helical scanning Rotation times for helical scanning (s) Number of simultaneous slices at each rotation time Pitches available for routine scanning (range and increment) Recommended pitches for optimal image quality 1 1, 1.5, 2, 3, 4, (option), slice : 1 4-slice : 0.75 & slice : 1 4-slice : 0.75 & freeely selectable None freely selectable None Helical interpolation algorithms available GE Proprietary algorithms (SmartHelical & MDMP, including CrossBeamTM & HyperplaneTM) Fan Beam SureView, AMPR conebeam artefact reduction Maximum number of rotations in one helical run at standard abdomen parameters 70sec ( ma) 90sec ( ma) 110sec ( ma) Maximum continuous scan time (s) 120 Limited by disc capacity and tube loading Limited by disc capacity and tube loading 160 (324mA,.5s) 176 (300mA,.5s) 200 (273mA,.5s) 100 Starting with a cold tube, the maximum helical scan distance using a 1 mm imaged slice thickness and a pitch of 1.5 (mm) 1600 Limited by disc capacity and tube loading 1570 Gantry tilt range for helical scanning (degrees) Table 10: Scan projection radiography (SPR) ± 30 ± 30 ± 30 Maximum SPR length (mm) SPR field dimensions (mm x mm) 500 x x x 1536 Angular positions of X-ray tube available for SPR (1 steps) AP, PA, LAT (±1 accuracy) Real time image No No Yes Accuracy of slice prescription from the scanogram (mm) Accuracy of distance measurements from SPR's taken at isocentre (lateral and axial directions) (mm) ± 0.25 ± 0.25 ± 0.5 < 2 x image pixel size ± 0.25 ±

12 Specification comparison Table 11: Manufacturers' performance data Spatial resolution (lp/cm) for sharpest clinical algorithm. Acquisition parameters in brackets. MTF0: 15.4 MTF10: 13.9 (10cm DFOV, Edge alg, Small Focus) MTF0 15 lp/cm MTF0: 15.4 ±10% MTF2: 14.5 ±10% (1s, 160 ma, 120 kv, 1.2 mm) Contrast resolution: smallest rod size (mm) discernable at given parameters in 20 cm CATPHAN mgy with 95%CL: 120kVp, 135mAs, 10mm, Std alg % CT number accuracy (HU) Water : ± 3 ± 4 CTDI settings for std head CTDI (mgy/100mas), centre of head phantom CTDI (mgy/100mas), periphery of head phantom CTDI settings for std body CTDI (mgy/100mas), centre of body phantom CTDI (mgy/100mas), periphery of body phantom 120 kvp, 260 mas, 2 x 10 mm Spiral: mgy: 120 kv, 140 mas 10 mm Air: ± 10 Water: ± kv 120 kv, 20 x 1.2 mm kvp, 260 mas, 2 x 10 mm 130 kv 20 x 1.2 mm Dose profile FWHM (mm) (focal spot size in brackets) 20: 20.6(l) 15: 16.5 (s) 10: 11.5 (s) 5: 6.7 (s) 1.25: 3.5 (s) 2 x 0.63:1.9(s) ± 10% for all collimations Info. not available 12

13 Specification comparison Table 12: Factors affecting image quality Post-patient collimation for narrow slices Automatic ma control (AEC / ma modulation) software No No No 3D Dose Modulation No Yes (CAREDose 4D) - ma adjustment for patient size Yes No Yes - ma adjustment along the z-axis Yes No Yes - ma modulation during rotation Yes No Yes Adaptive filtration for noise reduction Low signal correction No Yes (automatic) Quarter detector shift Yes No Yes Moving (dynamic/flying) focal spot No No Yes Number of imaging detectors per row Sampling frequency (Hz) s scan (hardware capable to 1760) 672 (1344 channels) 2400 Max Artefact reduction algorithms Cone beam correction Iterative Bone Option (IBO), Motion correction, Recon of thick slices from thinner ones GE Proprietary algorithms (SmartHelical & MDMP, including CrossBeamTM & HyperplaneTM) No Not required Modified beam hardening (abdomen, pelvis, shoulder), Motion correction (sequential modes), Posterior Fossa optimisation Yes, SureView and AMPR cone-beam artefact reduction 13

14 Table 13: Operator's console Specification comparison Diagonal dimension of image screen (inches) CRT 18.1 Number of monitors at console (functions of each if > 1) 2 (patient info and technique selection / image display) 1 1 acquisition and optional 1 x review and processing shared database console Image area matrix dimensions 512 x 512, 768 x 768, 1024 x x x 1024 Usual range of CT Number displayed (HU) to to to (-10,240 to 30,710 if metal implants) Accuracy of distance measurements in x-y plane (mm) < 2 times image pixel size ± 0.25 depends on pixel size Weighted CTDI (CTDIw or CTDIvol) displayed on console Dose Length Product (DLP) displayed on console Geometric Efficiency displayed on console when <70% Control methods Yes No Yes Yes No Yes Yes No No Mouse, trackball, keyboard Mouse, keyboard Mouse, keyboard Table 14: Main computer Make and model HP XW8000 Sun Ultrasparc Siemens PC compatible with array processors Operating system Linux RedHat 7.3 Unix Windows XP Type and speed of CPU 2 x 2.66 GHz 64 bit RISC Amount of computer RAM supplied as standard (Gbytes) Maximum amount of computer RAM (Gbytes) 10 x Pentium Xeon 3.2 GHz Info. not available 18 14

15 Specification comparison Table 15: Image storage Total standard hard disk capacity (Gbytes) Maximum hard disk capacity (Gbytes) Hard disk capacity for image storage (Gbytes and no. of uncompressed 512x512 images) 146 (250,000 images) 26 (11,000 data files) 146 (260,000 images) Hard disk capacity for storage of raw data files (Gbytes and no. of data files) 72 ( slice axial raw data files) 26 (1,000 raw data files) 300 Archive options MOD [images] & DVD [scan data, protocols] (standard) Tape (standard) MOD Option MOD and CD writer (standard) Capacity of a single archive disk (Gbytes and no. of images) 4.6 (9400 losslessly compressed 512x512 images or 700 raw data files) Tape 6500 Images per cartridge 2.3 Gb MOD 1400 Images MOD: 4.1GB (26,000 lossless images), CD- R: 0.65GB (4100 lossless images) 512 x 512 Time to mount an archive disk or tape (s) 5-6 in background operation Tape - depends upon images requested Immediate (disk continually accessible) Approx 30 for full disk Archive data transfer rate (images / s) 1 (read) 0.7 (write) >

16 Specification comparison Table 16: Image reconstruction on main console Reconstruction matrix Minimum reconstruction interval in helical scanning (mm) Reconstruction time from the start of data acquisition to the appearance of the 30th image of a series for a standard axial brain scan (s) (with IBO) 90 3 (up to 20 f/s) Reconstruction time from the start of data acquisition to the appearance of the 30th image of a series for an axial spine scan (s) (up to 20 f/s) Reconstruction time from the start of data acquisition to the appearance of the 30th image of a series for a helical abdomen scan (s) (up to 20 f/s) Simultaneous scanning and reconstruction Any delay in either scanning or reconstruction when performed concurrently Simultaneous scanning and routine analysis Yes No Yes No Info. not available No Yes Yes Yes Simultaneous scanning and archiving and/or hard copying Simultaneous scanning and transfer to second console/workstation Yes Yes Yes Yes Yes Yes 16

17 Table 17: 3D reconstruction display Specification comparison MIPs and MinIPs (maximum and minimum intensity projections) MC-standard WS-standard (MIP & MinIP) MC-standard WS-standard (Angio MIP) MC-standard SSD (3D Shaded Surface Display) WS-standard (3D) MC-standard WS-standard (3D SSD) MC-standard 3D Volume rendering software WS-standard (Volume Rendering) MC-Option WS-standard (Vol Rend 4D Angio) 3D Virtual endoscopy WS-standard (Navigator) Option MPR (Multi-planar reconstruction) MC-standard WS-standard (MPR & MPVR) MC-standard WS-standard (MPR) MC-standard Planes available in MPR Axial, para-axial, sagittal, coronal, oblique, curvilinear All planes, any oblique Axial, sagittal, coronal, oblique, curvilinear 17

18 Specification comparison Table 18: Optional facilities Contrast injector Option Option Option Contrast media bolus tracking Standard (SmartPrep) Not available CT fluoroscopy software and hardware Option (SmartStep) Not available Standard (CAREBolus) Option (CAREVision with HandCARE) Hard-copy imaging device Option Option Option Radiotherapy planning table top Option (RT flat pad and Exact couch top) Standard Option Carbon fibre breast board Option Option Option Means for attaching patient immobilisation devices and a stereotactic frame to the end of the couch Option (Exact couch) Option Option Bone Mineral Densitometry MC-Not available (BMD) (Osteo CT) CT Angiography MC-standard WS-standard AVA (Vessel Assessment) option on WS WS option MC-standard basic package Dental Radiotherapy CT simulation software Prospective ECG-triggered cardiac software Retrospective ECG-gated cardiac software CT Perfusion software (Dentascan) MC-Not available (CT sim) (SmartScore) MC-Not available MC & (Cardiac Imaging) (CT Perfusion) WS option Not available Not available WS option (Dental CT) Coherence Dosimetrist (separate workstation) Not available Not available (Perfusion CT) 18

19 Table 19: Installation requirements Specification comparison Environmental requirements (max/min temperature, humidity) in scanner room ºC, 30-60% relative humidity C, 30-60% relative humidity ºC, 15-75% relative humidity Environmental requirements (max/min temperature, humidity) in scanner control room ºC, 30-60% relative humidity C, 30-60% relative humidity ºC, 15-75% relative humidity Peak heat output from system during scanning (kw) (add 0.07 for CT fluoro) System cooling method Output to air Water - air Water - water Air conditioning requirements for scanner room of minimum floor area Minimum floor area required for the system (m²) Recommended To meet environmental requirements None Gantry dimensions (H x W x D (mm)) and weight (kg) 1992 x 2439 x 1007, 1701kg 1960 x 2240 x 863, 1532 kg 1990 x 2280 x 940, 2000 kg Couch dimensions (H x W x L (mm)) and weight (kg) 1121 x 610 x 2387, 330kg 560 x 340 x 1680, 550kg 1022 x 690 x 2430, 500 kg Supplementary unit dimensions (H x W x D (mm)) and weight (kg) Power supply requirements Power Unit: 1067 x 711 x 559, 350kg 3 phase V, 150kVA None 3 phase V, 75 kva Power unit: 1815 x 905 x 800, 550kg Cooling unit: 1815 x 905 x 860, 200kg 3 phase V, 66-80kVA 19

20 Table 20: Independent workstation Specification comparison Is a workstation provided? Yes No, option (Brilliance Extended Workspace) No, option (LEONARDO) Computer make and model HP XP8000 Dell Xeon Siemens Fujitsu Xeon Operating system Linux Red Hat 7.3 Windows XP Windows XP Type and speed (GHz) of CPU 2 x x x Xeon 3.2 Amount of computer RAM supplied as standard (Gbytes) Maximum amount of computer RAM (Gbytes) Total hard disk storage capacity supplied as standard (Gbytes) Maximum total hard disk storage capacity (Gbytes) Archive options Capacity of a single archive disk (Gbytes) Environmental requirements (max/min temperature, humidity) for workstation CD-R standard MOD optional CD-R standard EOD option ºC, % relative humidity 0-40 C CD-R standard MOD option MOD: 4.1 CD-R: ºC, 20-80% relative humidity 20

21 Specification comparison Table 21: Image transfer and connectivity Speed of scanner / workstation connections to local area networks (Mbits/s) Remote PC access to images on workstation DICOM services on Main Console or Option Option (Easyweb) Option Storage SCU, SCP SCU, SCP SCU, SCP Print SCU SCU SCU Query / retrieve SCU, SCP SCU, SCP SCU, SCP Modality worklist Option Option SCU Performed procedure step Option Option SCU Storage commitment Not available Option SCU DICOM services on Workstation Storage SCU, SCP SCU, SCP SCU, SCP Print SCU SCU SCU Query / retrieve SCU, SCP SCU, SCP SCU, SCP Modality worklist management Not available Not available Not available Performed procedure step Not available Not available Not available Storage commitment Not available Not available SCU. 21

22 Appendix 1: ImPACT and the MHRA Background One of the roles of the Medicines and Healthcare products Regulatory Agency (MHRA) is to fund evaluation programmes for medical devices and equipment. The programme includes evaluation of x-ray Computed Tomography Equipment currently available on the UK market. MHRA aims to ensure that evaluation techniques keep abreast of improvements in CT imaging performance and that MHRA reports present evaluation information that is timely, useful and readily understood. ImPACT ImPACT (Imaging Performance Assessment of Computed Tomography) is the MHRA's CT evaluation facility. It is based at St George's Hospital, London, part of St George's Healthcare NHS Trust. ImPACT have developed test objects and measurement procedures suitable for inter-comparing CT scanner performance. For each CT evaluation hundreds of images are obtained from the system under test and subsequently analysed using custom written software. Dose measurements are made using ion chambers, and x- ray film is used to obtain additional x-ray dose information. MHRA support to purchasers and users The ImPACT team is available to answer any queries with regard to the details of this report, and also to offer general technical and user advice on CT purchasing, acceptance testing and quality assurance. ImPACT Bence Jones Offices St George s Hospital London SW17 0QT T: +44 (0) F: +44 (0) E: impact@impactscan.org W: MHRA contact point for general information on the CT evaluation programme: Device Evaluation Service MHRA Elephant and Castle London SE1 6TQ T: +44 (0) F: +44 (0) E: des@ mhra.gsi.gov.uk W: www. mhra.gov.uk 22